Photoreceptors are used in printing/copying devices. In particular, the manufacture of a photoreceptor substrate with a more evenly distributed surface energy is described.
In xerography, or electrophotographic printing/copying, a charge-retentive device called a photoreceptor is electrostatically charged. For optimal image production, the photoreceptor should be uniformly charged across its entire surface. The photoreceptor may then be exposed to a light pattern of an input image to selectively discharge the surface of the photoreceptor in accordance with the image. The resulting pattern of charged and discharged areas on the photoreceptor forms an electrostatic charge pattern (i.e., a latent image) conforming to the input image. The latent image may be developed by contacting it with finely divided electrostatically attractable powder called toner. Toner may be held on the image areas by electrostatic force. The toner image may then be transferred to a substrate or support member (e.g., paper) and the image may then be affixed to the substrate or support member by a fusing process to form a permanent image thereon. After transfer, excess toner left on the photoreceptor may be cleaned from the photoreceptor surface and residual charge may be erased from the photoreceptor.
Electrophotographic photoreceptors may be provided in a number of forms. For example, a photoreceptor may be a homogeneous layer of a single material, such as vitreous selenium, or a photoreceptor may be a composite layer containing a photoconductive layer and another material. In addition, the photoreceptor may be multi-layered. Current layered photoreceptors generally have at least a flexible substrate support layer, or undercoat layer (UCL), and two active layers. These two active layers generally include a charge generating layer (CGL) containing a light absorbing material, and a charge transport layer (CTL) containing electron donor molecules. These layers may be in any order, and sometimes may be combined in a single or a mixed layer. The flexible substrate support layer may be formed of a conductive material. Alternatively, a conductive layer may be formed on top of a nonconductive flexible substrate support layer.
U.S. Pat. No. 5,958,638 to Katayama, et al. discloses exemplary known materials used for undercoat layers. For example, such materials may include a resin material alone, such as polyethylene, polypropylene, polystyrene, acrylic resin, vinyl chloride resin, vinyl acetate resin, polyurethane, epoxy resin, polyester, melamine resin, silicone resin, polyvinyl butyryl, polyamide and copolymers containing two or more of repeated units of these resins. The resin materials may further include casein, gelatin, polyvinyl alcohol, ethyl cellulose, etc. The undercoat layers are typically formed by a dip coating method. See, for example, U.S. Pat. No. 5,958,638 and U.S. Pat. No. 5,891,594 to Yuh, et al. In an exemplary dip coating process, a cylindrical drum may be dipped into a tank of coating material and then withdrawn, with a portion of the coating material adhering to the drum. The adhered coating material is then allowed to cure.
U.S. Pat. No. 6,331,371 to Matsui describes an electrophotographic photoreceptor that has a conductive support and a photoconductive layer laminated on the conductive support. A described exemplary conductive support is made of aluminum or aluminum based alloy, and the maximum height of the surface roughness of the conductive support is 0.8 μm or more and 2.0 μm or less. Further, the reflectivity of light incident upon the surface of the conductive support is equal to or less than 35% of a quantity of exposure light from a coherent light. The described photoreceptor produces a quantity of reflected lights in response to a coherent light and thereby suppresses a quantity of interference lights produced by the reflected lights and reflected lights from or incident lights on the photoconductive layer. In this manner the photoreceptor prevents generation of interference fringe patterns upon printed output.
U.S. Pat. No. 6,051,148 to Perry et al. describes a method of fabricating a multi-layered photoreceptor in which a photoreceptor substrate having a metal surface is etched with an etching solution and a metal oxide layer is formed on the metal surface with the etching solution. The etching and oxidation layer creates a roughened substrate surface that scatters rather than reflects light. This light scatter effect reduces interference patterns caused by reflected beams of coherent light reflected from each of the respective interfaces between layers in the multi-layered photoreceptor.
U.S. Pat. No. 5,997,722 to Vidal et al. describes an aqueous cleaning method for a photoreceptor that includes analyzing the finished substrate surface by performing a first surface energy reading, a first ellipsometry reading, a first x-ray diffraction reading, and a first profilometry reading, removing electrochemically via an alternating voltage or alternating current a portion of the finished substrate surface, thereby resulting in a cleaned substrate surface, analyzing the cleaned substrate surface by performing a second surface energy reading, a second ellipsometry reading, a second x-ray diffraction reading, and a second profilometry reading, in which the removing step is accomplished to the extent that the second surface energy reading and the second ellipsometry reading are measurably changed from the first surface energy reading and the first ellipsometry reading, but the second x-ray diffraction reading and the second profilometry reading are measurably unchanged from the first x-ray diffraction reading and the first profilometry reading; and depositing a layer of the photoreceptor on the cleaned substrate surface.
U.S. Pat. No. 5,635,324 to Rasmussen et al. describes a method for eliminating interference between the photoreceptor substrate and the undercoat layer interface, the substrate is formed to include a surface texture that is optimal for enabling continuous coating of thin-film forming undercoat layer materials such as organometallic or organometallic chelate compounds with a silane having a dried coated thickness between approximately 0.05-0.5 μm and preferably between 0.08-0.12 μm. In order for the substrate to accommodate a thin layer of such undercoat materials, the substrate of the photoreceptor is designed to have a specific surface roughness.
U.S. Pat. No. 5,381,213 to Michlin describes an adapter that allows a lathe to turn photoreceptor substrate drums, charge rollers and developer brushes of printers, copiers, and facsimile machines. A unitary component adapts the drum so it may be held on the lathe and drives the object. The adapting portion includes a flexible material such as a hose or o-ring to snugly receive the end extension of the drum, roller or brush. The drive portion connects with the drive bolt of the lathe and spins the object.
U.S. Pat. No. 5,346,556 to Perry et al. describes a method of cleaning a substrate that includes: lathing a substrate surface with a cutting fluid composition containing an antioxidant, a surfactant, a lubricant, and water; rinsing the lathed substrate surface with high quality deionized water having a resistivity of at least 2 M ohm-cm; immersing the rinsed lathed substrate surface in a bath of high quality deionized water having a resistivity of at least 2 M ohm-cm; and removing the substrate from the bath of deionized water at a rate low enough to prevent water droplets from forming on the substrate.
U.S. Pat. No. 5,309,200 to Michlin describes a set of adapter units which allow a powerful, variable speed lathe to turn photoreceptor drums, charge rollers and developer brushes of printers, copiers, and facsimile machines. In one embodiment, adapter units fit over the cylindrical extensions on the ends of the drum. Two pieces of opposing tail stock support and hold the drum on the lathe by applying pressure against the adapter units. A drive bushing is attached to and rotates with the drive bolt of the lathe.
U.S. Pat. No. 5,228,369 to Itoh et al. describes a method for machining a substrate surface of a photoreceptor by the use of a cutting machine which supplies cutting lubricant from a reservoir to a cutting tool of the cutting machine, the method comprises a measurement of the cutting tool temperature by a sensor and a control of both the temperature of cutting lubricant and a flow rate thereof. The control is responsive to the cutting tool temperature and suppresses a temperature fluctuation of the cutting tool.
U.S. Pat. No. 5,170,683 to Kawada et al. describes a method of surface-processing a photoreceptor base including aluminum material for electrophotography on a lathe. A surface of the a photoreceptor base is cut by a cutting tool having a polycrystalline diamond body while cutting fluid, composed of water, an aqueous solution of a surface-active agent or an aqueous solution of a water-soluble organic solvent, is supplied to the surface of the photoreceptor base.
U.S. Pat. No. 5,003,851 to Kawada et al. describes a method of manufacturing a photoreceptor base drum by a lathe-turning machine in which a cutting tool is brought in contact with a surface of the base drum and travels in the axial direction to finish the surface of the base drum into a mirror-like surface. A main cutting edge formed by a rake surface and a front flank surface on the cutting tool is shaped as a curved surface with a radius of curvature of 0.15 to 3.5 μm, and the rake surface and the front flank surface are shaped to smoothly continue to the curved surface of the main cutting edge.
U.S. Pat. No. 5,919,594 to Perry et al. and U.S. Pat. No. 5,573,445 to Rasmussen et al. describe methods of roughening a photoreceptor substrate by spraying a honing composition including a particulate matter against a photoreceptor substrate to create a predetermined surface roughness.
All of the references indicated above are herein incorporated by reference in their entirety for their teachings.